High-Grade Mucoepidermoid Carcinoma Ex Metastasizing Pleomorphic Adenomas in the Parotid Gland and Parapharyngeal Space: a Case Report and Literature Review

Pleomorphic adenoma is the most common benign neoplasm of the salivary glands. Its three malignant variants include carcinoma ex pleomorphic adenoma, carcinosarcoma, and metastasizing pleomorphic adenoma. Among the subtypes of carcinoma ex pleomorphic adenoma, high-grade mucoepidermoid carcinoma has rarely been reported. Additionally, metastasizing pleomorphic adenoma is rare.We report the imaging findings of a high-grade mucoepidermoid carcinoma ex metastasizing pleomorphic adenoma of the parotid gland and parapharyngeal space in a 42-year-old man.

High-Grade Mucoepidermoid Carcinoma Ex Metastasizing Pleomorphic Adenomas in the Parotid Gland and Parapharyngeal Space: a Case Report and Literature Review

Pleomorphic adenoma is the most common benign neoplasm of the salivary glands. Its three malignant variants include carcinoma ex pleomorphic adenoma, carcinosarcoma, and metastasizing pleomorphic adenoma. Among the subtypes of carcinoma ex pleomorphic adenoma, high-grade mucoepidermoid carcinoma has rarely been reported. Additionally, metastasizing pleomorphic adenoma is rare.We report the imaging findings of a high-grade mucoepidermoid carcinoma ex metastasizing pleomorphic adenoma of the parotid gland and parapharyngeal space in a 42-year-old man.

Diagnostic Role of Parotid Computed Tomography for Identifying Sjögren’s Syndrome / 대한이비인후과학회지

Background and Objectives@#Sjögren’s syndrome (SS) is an autoimmune inflammatory disorder of exocrine glands characterized by dry mouth and eye. Recently, ultrasonography has become a valuable tool for the assessment of salivary gland involvement in SS although studies on the usefulness of salivary gland CT is rare. In this regard, we evaluated the diagnostic accuracy of parotid gland CT for SS.Subjects and Method A total of 91 patients with sicca symptoms took a parotid CT, a serology test, an ophthalmologic examination and a minor salivary gland biopsy. At the end, as a standard, we diagnosed the primary SS according to the new 2016 American College of Rheumatology/ European League Against Rheumatism classification criteria. The diagnostic value of parotid CT was compared by the McNemar test. @*Results@#Of the total of 91 patients with parotid CT, 37 (40.7%) patients met the SS classification criteria. On the parotid CT, heterogeneity of the parotid gland has the sensitivity of 74.1%, specificity of 70.3%, and accuracy of 71.4%. The abnormal fat tissue deposition showed the sensitivity of 74.1%, specificity of 81.3%, and accuracy of 79.1%. Diffuse calcification was seen in 1/91 SS patients (sensitivity 3.7%, specificity 100%, accuracy 71.4%). @*Conclusion@#Parotid CT is helpful for the diagnosis of SS. The presence of heterogeneity and fat tissue deposition are highly sensitive for the accuracy of SS. Diffuse calcification in bilateral parotid glands is highly specific for SS.

Transfusional Iron Overload and Choroid Plexus Hemosiderosis in a Pediatric Patient: Brain Magnetic Resonance Imaging Findings

Hemosiderosis is characterized by the deposition of excess iron in body tissues. The choroid plexus is an important part of the central nervous system that can be the primary site of iron overload. T2*-weighted gradient echo (GRE) sequence provides high sensitivity for demonstrating cerebral microhemorrhagic foci and iron deposition. In the present study, we describe the case of a 15-year-old boy with acute lymphoblastic leukemia, in whom repeated transfusion led to iron accumulation in the brain. GRE sequence effectively demonstrated hemosiderin deposition in the choroid plexus.

Rapidly Growing Anaplastic Ganglioglioma Mimicking Brain Metastasis in a Middle-Aged Woman: A Case Report

Anaplastic gangliogliomas (AGGs), the malignant counterpart of gangliogliomas, are classified as grade III tumors by the World Health Organization. Although, the clinical course and optimal treatment of AGGs are not well understood, they often result in worse local control rate and shorter survival. The authors describe the magnetic resonance imaging findings of a middle-aged woman with supratentorial AGG, that manifested as a rapidly growing cystic mass which mimicked metastasis. The authors suggest that AGG may be considered as a possible diagnosis for a rapidly growing peripheral enhancing mass in the brain, especially when it is superficially located.

Magnetic Resonance Imaging Findings of Mumps Meningoencephalitis with Bilateral Hippocampal Lesions without Preceding Acute Parotitis: A Case Report

Meningitis is a common central nervous system (CNS) complication of the mumps, a viral infection, but encephalitis and meningoencephalitis are less common in mumps. We describe magnetic resonance imaging findings of acute mumps meningoencephalitis in a 32-year-old male who showed bilateral hippocampal lesions without preceding parotitis. Although it is rare, hippocampal involvement should be considered a CNS complication of mumps infection.

Improvement of Fat Suppression and Artifact Reduction Using IDEAL Technique in Head and Neck MRI at 3T

PURPOSE: To quantitatively and qualitatively compare fat-suppressed MRI quality using iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) with that using frequency selective fat-suppression (FSFS) T2- and postcontrast T1-weighted fast spin-echo images of the head and neck at 3T. MATERIALS AND METHODS: The study was approved by our Institutional Review Board. Prospective MR image analysis was performed in 36 individuals at a single-center. Axial fat suppressed T2- and postcontrast T1-weighted images with IDEAL and FSFS were compared. Visual assessment was performed by two independent readers with respect to; 1) metallic artifacts around oral cavity, 2) susceptibility artifacts around upper airway, paranasal sinus, and head-neck junction, 3) homogeneity of fat suppression, 4) image sharpness, 5) tissue contrast of pathologies and lymph nodes. The signal-to-noise ratios (SNR) for each image sequence were assessed. RESULTS: Both IDEAL fat suppressed T2- and T1-weighted images significantly reduced artifacts around airway, paranasal sinus, and head-neck junction, and significantly improved homogeneous fat suppression in compared to those using FSFS (P < 0.05 for all). IDEAL significantly decreased artifacts around oral cavity on T2-weighted images (P < 0.05, respectively) and improved sharpness, lesion-to-tissue, and lymph node-to-tissue contrast on T1-weighted images (P < 0.05 for all). The mean SNRs were significantly improved on both T1- and T2-weighted IDEAL images (P < 0.05 for all). CONCLUSIONS: IDEAL technique improves image quality in the head and neck by reducing artifacts with homogeneous fat suppression, while maintaining a high SNR.

Computed Tomography and Magnetic Resonance Imaging Findings of Nasal Cavity Hemangiomas According to Histological Type

OBJECTIVE: To compare computed tomography (CT) and magnetic resonance imaging (MRI) findings between two histological types of nasal hemangiomas (cavernous hemangioma and capillary or lobular capillary hemangioma). MATERIALS AND METHODS: CT (n = 20; six pre-contrast; 20 post-enhancement) and MRI (n = 7) images from 23 patients (16 men and seven women; mean age, 43 years; range, 13-73 years) with a pathologically diagnosed nasal cavity hemangioma (17 capillary and lobular capillary hemangiomas and six cavernous hemangiomas) were reviewed, focusing on lesion location, size, origin, contour, enhancement pattern, attenuation or signal intensity (SI), and bony changes. RESULTS: The 17 capillary and lobular hemangiomas averaged 13 mm (range, 4-37 mm) in size, and most (n = 13) were round. Fourteen capillary hemangiomas had marked or moderate early phase enhancement on CT, which dissipated during the delayed phase. Four capillary hemangiomas on MRI showed marked enhancement. Bony changes were usually not seen on CT or MRI (seen on five cases, 29.4%). Half of the lesions (2/4) had low SI on T1-weighted MRI images and heterogeneously high SI with signal voids on T2-weighted images. The six cavernous hemangiomas were larger than the capillary type (mean, 20.5 mm; range, 10-39 mm) and most had lobulating contours (n = 4), with characteristic enhancement patterns (three centripetal and three multifocal nodular), bony remodeling (n = 4, 66.7%), and mild to moderate heterogeneous enhancement during the early and delayed phases. CONCLUSION: CT and MRI findings are different between the two histological types of nasal hemangiomas, particularly in the enhancement pattern and size, which can assist in preoperative diagnosis and planning of surgical tumor excision.

Meningovascular and Spinal form of Neurosyphilis Presenting as Multiple Cranial Nerve Palsy, Cerebral Infarction and Meningomyelitis in a Human Immunodeficiency Virus Negative-Patient: MR Imaging Features

Neurosyphilis is a rare infection of the brain and spinal cord caused by a spirochete named Treponema pallidum. We describe the magnetic resonance imaging of a 53-year-old man with syphilis who manifested as both meningovascular, and spinal meningomyelitic types, which involved the optic, trigeminal, facial and vestibulocochlear nerves, both middle and left posterior cerebral arteries, thoracic spinal cord and meninges of the lumbar spine. This case report suggests that neurosyphilis should be considered as a possible diagnosis in patients showing complex brain and spinal imaging features. These features include enhancing meningeal lesions with multiple cranial nerve involvement, stenoses in large to medium size cerebral arteries, and intramedullary and meningeal lesions of spine.

The Secondary Contiguous or Non-contiguous Subchondral Bone Impactions in Subaxial Cervical Spinal Injury: Incidence and Associated Primary Injury Patterns

PURPOSE: To evaluate the incidence of secondary contiguous or non-contiguous subchondral bone impactions (SBI) in subaxial cervical spinal injury and associated primary injury patterns. MATERIALS AND METHODS: A retrospective review of computed tomography, magnetic resonance imaging, and medical records was carried out for 47 patients who had sustained a subaxial cervical spinal injury. Presence, number, level, and sites of secondary contiguous or non-contiguous SBI were recorded. To evaluate primary injury patterns, the level and number of primary injury sites of subaxial cervical spine injury, injury morphology, anterior/posterior discoligamentous complex (ADC/PDC) injury, posterior ligamentous complex (PLC) injury, spinal cord injury, and mechanism of injury (MOI) were analyzed. Differences in primary injury pattern of subaxial cervical spine injury and MOI between patients with and without SBI, and between contiguous or non-contiguous SBI were analyzed using the Mann-Whitney U test, Pearson's chi square test and Fisher's exact test. RESULTS: Eighteen patients (18/47, 38.29%) had developed contiguous (n=9) or non-contiguous (n=9) SBI, most commonly involving T3 (15/47, 31.91%) and 3 levels (6/18, 33.33%). All SBIs had developed near the anterosuperior region of the body and the superior endplate and were the result of a high-impact MOI. SBIs were statistically significant in association with injury morphology and PLC injury (P=0.001, P=0.009, respectively) at the primary injury site. Non-contiguous SBI was more frequently accompanied by upper cervical spinal injuries in association with PDC injuries, as opposed to contiguous SBI, with statistical significance (P=0.009), while no other statistically significant differences were found. CONCLUSION: Secondary SBIs are common and probably associated with subaxial cervical spinal injuries with high energy compressive flexion forces.

H1 Magnetic Resonance Spectroscopy of Cystic Ovarian Lesions

On H1 MRS (magnetic resonance spectroscopy), malignant tumors show higher concentration of metabolite than benign lesions. Lactate double peak was detected in malignant tumor and endometriosis, and more prominent high concentration was demonstrated in endometriosis. Tuboovarian abscesses and salpingitis do not show prominent peak. Dermoid cysts show high levels of lipid peak. Paratubal cyst and follicular cyst can be showed the lipid peak, however, the concentration of lipid is lower than that of dermoid cyst. H1 MRS of ovarian cystic lesions can give valuable information about the presence of metabolites of ovarian cystic lesions.

Brain Stem Hypoplasia Associated with Cri-du-Chat Syndrome

Cri-du-Chat syndrome, also called the 5p-syndrome, is a rare genetic abnormality, and only few cases have been reported on its brain MRI findings. We describe the magnetic resonance imaging findings of a 1-year-old girl with Cri-du-Chat syndrome who showed brain stem hypoplasia, particularly in the pons, with normal cerebellum and diffuse hypoplasia of the cerebral hemispheres. We suggest that Cri-du-Chat syndrome chould be suspected in children with brain stem hypoplasia, particularly for those with high-pitched cries.

1H MR Spectroscopy of the Normal Human Brains: Comparison between Signa and Echospeed 1.5 T system

PURPOSE: To evaluate the usefulness and reproducibility of 1H MRS in different 1.5 T MR machines with different coils to compare the SNR, scan time and the spectral patterns in different brain regions in normal volunteers. MATERIALS AND METHODS: Localized 1H MR spectroscopy (1H MRS) was performed in a total of 10 normal volunteers (age; 20-45 years) with spectral parameters adjusted by the autoprescan routine (PROBE package). In all volunteers, MRS was performed in a three times using conventional MRS (Signa Horizon) with 1 channel coil and upgraded MRS (Echospeed plus with EXCITE) with both 1 channel and 8 channel coil. Using these three different machines and coils, SNRs of the spectra in both phantom and volunteers and (pre)scan time of MRS were compared. Two regions of the human brain (basal ganglia and deep white matter) were examined and relative metabolite ratios (NAA/Cr, Cho/Cr, and mI/Cr ratios) were measured in all volunteers. For all spectra, a STEAM localization sequence with three-pulse CHESS H2O suppression was used, with the following acquisition parameters: TR=3.0/2.0 sec, TE=30 msec, TM=13.7 msec, SW=2500 Hz, SI=2048 pts, AVG=64/128, and NEX=2/8 (Signa/Echospeed). RESULTS: The SNR was about over 30% higher in Echospeed machine and time for prescan and scan was almost same in different machines and coils. Reliable spectra were obtained on both MRS systems and there were no significant differences in spectral patterns and relative metabolite ratios in two brain regions (p>0.05). CONCLUSION: Both conventional and new MRI systems are highly reliable and reproducible for 1H MR spectroscopic examinations in human brains and there are no significant differences in applications for 1H MRS between two different MRI systems.

Usefulness of Helical CT in the Diagnosis of Strangulation in Small Bowel Obstruction

PURPOSE: We wished to evaluate the usefulness of helical CT for the diagnosis of strangulation of the dilated small bowels. MATERIALS AND METHODS: The CT scans of 31 patients with small bowel obstruction from various causes were reviewed retrospectively. Thirteen of these patients were confirmed as small bowel strangulation by surgery and pathology. Fourteen patients underwent surgery, but they had no strangulation. Three patients were reduced by using a nasogastric tube and one infant with intussusception was reduced by air reduction. The following CT findings of strangulation were evaluated: reduced bowel wall enhancement by visual assessment and measuring the HU, ascites, thickening of bowel wall, abnormal mesenteric vessel location and whirlpool appearance, and mesenteric venous engorgement. For the precise evaluation of reduced bowel wall enhancement, the HUs were measured by 1 mm2 of ROI, and the differences of HUs between the well enhanced bowel and poorly enhanced bowel were compared. RESULTS: For the diagnosis of strangulation, measurement of HU of the bowel wall could improve the sensitivity from 69% to 100%. The specificity of both methods, by visual assessment and measurement of HU, was 94%. Ascites had a sensitivity of 69% and specificity of 44%. Thickening of bowel wall had a sensitivity of 38% and specificity of 78%. Abnormal mesenteric vessel location and whirlpool appearance had a sensitivity of 38% and specificity of 83%. Mesenteric venous engorgement had a sensitivity of 31% and specificity of 72%. CONCLUSION:Measurement of HU of the bowel wall after contrast enhancement can be a useful method in the differential diagnosis between the strangulated and non-strangulated bowels in patients with small bowel obstruction.

Sinus Pericranii in an Infant: MR Imaging and Angiographic Findings

Sinus pericranii is a rare vascular anomaly involving abnormal communication between the intracranial and extracranial venous circulations. Although the condition can be diagnosed clinically, imaging is required to distinguish it from other entities and to identify the connection between the extracranial and intracranial dural venous sinus. We report the characteristic MR imaging and angiographic findings of a case of sinus pericranii.